Q. Given the function f(x)=(−7x3−2)(5x2−6+2x−3), find f′(x) in any form.Answer: f′(x)=
Identify Functions: To find the derivative of the function f(x)=(−7x3−2)(5x2−6+2x−3), we will use the product rule. The product rule states that the derivative of a product of two functions is the derivative of the first function times the second function plus the first function times the derivative of the second function.
Find u′(x): First, let's identify the two functions that we will be differentiating. We have u(x)=−7x3−2 and v(x)=5x2−6+2x−3.
Find v′(x): Now, we need to find the derivative of u(x), which is u′(x). The derivative of −7x3 is −21x2, and the derivative of a constant is 0. So, u′(x)=−21x2.
Apply Product Rule: Next, we need to find the derivative of v(x), which is v′(x). The derivative of 5x2 is 10x, the derivative of −6 is 0, and the derivative of 2x−3 is −6x−4 (using the power rule). So, v′(x)=10x−6x−4.
Expand Terms: Now we can apply the product rule: f′(x)=u′(x)v(x)+u(x)v′(x). Substituting the derivatives we found, we get f′(x)=(−21x2)(5x2−6+2x−3)+(−7x3−2)(10x−6x−4).
Simplify Terms: We will now expand the terms: f'(x) = \(-21x^2(5x^2) - 21x^2(−6) - 21x^2(2x^{−3}) - 7x^3(10x) - 7x^3(−6x^{−4}) - 2(10x) - 2(−6x^{−4})\.
Combine Like Terms: Simplify the terms: f′(x)=−105x4+126x2−42x−1−70x4+42x−1−20x+12x−4.
Combine Like Terms: Simplify the terms: f′(x)=−105x4+126x2−42x−1−70x4+42x−1−20x+12x−4.Combine like terms: f′(x)=(−105x4−70x4)+126x2−20x+(42x−1−42x−1)+12x−4.
Combine Like Terms: Simplify the terms: f′(x)=−105x4+126x2−42x−1−70x4+42x−1−20x+12x−4.Combine like terms: f′(x)=(−105x4−70x4)+126x2−20x+(42x−1−42x−1)+12x−4.After combining like terms, we get: f′(x)=−175x4+126x2−20x+12x−4.
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